The present invention relates to a new and distinct Campanula plant that is given the cultivar name of ‘Summertine Blues’. Campanula is in the family Campanulaceae. Campanula ‘Summertime Blues’ originated from a planned cross between Campanula punctata ‘Bowl of Cherries’ (U.S. Plant Pat. No. 13,194), as the seed parent, and Campanula trachelium ‘Bernice’ (an unpatented plant), as the pollen parent. The offspring from the cross were planted out and this selection was made for its fine characteristics.